Open Access

ARTICLE

H. Payer¹, T. Haschke¹, R. Reichardt¹, G. Li², K. Graf^2,3, W. Wiechert^1,3
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 61-76, 2008, DOI:10.3970/fdmp.2008.004.061
Abstract Microstructured surfaces are of steadily increasing importance in a large variety of technological applications. For the purpose of quality assurance, e.g. during variation studies of experimental parameters or for comparison with results from simulations, the surface geometry must be precisely measured and described in terms of geometric parameters. An analysis tool for regularly structured surfaces is presented that performs a highly automated evaluation of surface scanning data and derives geometric quality control parameters. To demonstrate the power of the analysis tool it is exemplarily applied for the investigation of microcraters emerging after the evaporation of… More >

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1999

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1213

Open Access

ARTICLE

Adeline Tchikango Siagam¹, Gunther Brenner¹, Peter Giese², Volker Wesling²
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 77-84, 2008, DOI:10.3970/fdmp.2008.004.077
Abstract The PTA (''Plasma-Transferred-Arc'') is a widespread variant of plasma powder processes to manufacture coatings against corrosion or abrasion. For the optimization of this technique, an explanation of the processes which lead to a maximal deposition performance (i.e. maximal quantity of powder converted per time) is required. Especially the gas and particle flow in the region between the burner nozzle and the work piece is of interest. In the present study, flow simulations (Computational Fluid Dynamics, CFD) have been done in order to investigate the determining factors for the dimensioning of the processes. Additionally, velocity measurements… More >

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1960

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1285

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ARTICLE

Viveca Wallqvist¹, Per M. Claesson², Agne Swerin¹, Patrick A. C. Gane^3,4,3, Joachim Schoelkopf³
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 85-98, 2008, DOI:10.3970/fdmp.2008.004.085
Abstract It has been shown that talc powder can be compacted into tablets with a preferred orientation of the platelets. The tablets can be obtained with different controlled porosity depending on pressing methods and applied pressure. The tablets can be obtained with or without additives, which may, in turn, be adsorbed. The orientation of the high aspect ratio platy talc, the surface chemistry imparted by the additives and the transported fluid influence the imbibition and permeation rates. Non-polar hexadecane displays a higher imbibition and permeability than water for all particulate orientations during short timescale absorption, likely… More >

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1594

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1160

Open Access

ARTICLE

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 99-112, 2008, DOI:10.3970/fdmp.2008.004.099
Abstract Levitation of liquid bodies against gravity is a contactless confinement process appropriate for manufacturing very pure materials. A variety of levitation techniques have been developed over the last few decades, such as aerodynamic, acoustic, electrostatic, microwave, and electromagnetic levitations. More recently, a new generation of novel techniques, essentially combinations of the established primary techniques, has been successfully introduced. Examples are acoustic-electric, aerodynamic-acoustic and acoustic-electromagnetic. The purpose of this series of papers in three parts, Bakhtiyarov and Siginer (2007a,b), is to review the advances in electromagnetic levitation (EML) since its introduction as a containerless melting technique, More >

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2005

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2000

Open Access

ARTICLE

S. Sabbaghi¹, M. Shariaty-Niassar², Sh. Ayatollahi¹, A. Jahanmiri¹
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 113-124, 2008, DOI:10.3970/fdmp.2008.004.113
Abstract In this study, the Onset of Asphaltene Precipitation is predicted by a modified Virial equation of state. The bases of quantum mechanics and statistical thermodynamics are used to evaluate the potential energy and intermolecular forces related to asphaltene molecules. The Virial equation of state is modified using group-contribution-methods for asphaltenes, which are assumed to be polymeric-like compounds consisting of aggregates of monodisperse asphaltene monomers. It is shown how the modified Virial equation of state with the Peneloux correction leads to estimate the molar volume and solubility parameter. These parameters are also compared successfully with results More >

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1568

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1309

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ARTICLE

Md. Tofiqul Islam¹, Sumon Saha², Md. Arif Hasan Mamun³, Mohammad Ali⁴
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 125-138, 2008, DOI:10.3970/fdmp.2008.004.125
Abstract A numerical study has been performed on mixed convection inside an open cavity on the bottom of a channel. One of the three walls of the cavity experiences a uniform heat flux while the other walls and the top of the channel are adiabatic. Three different cases are considered by applying uniform heat flux on (a) the inflow side (assisting forced flow); (b) the outflow side (opposing forced flow); (c) the bottom horizontal surface (transverse flow). The Galerkin weighted residual method of finite element formulation is used to discretize the governing equations. For mixed convection,… More >

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1663

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1296